Approximations of the Exchange and Correlation Potentials
A review is made of the approximate exchange and correlation potentials. A calculation of the gradient correction to the exchange potential is presented and the systematic expansion of the potentials in powers of the gradients of the density is critically examined. A related question concerning the validity of the local exchange raised by Overhauser is investigated here.
KeywordsLocal Density Approximation Correlation Potential Exchange Operator Density Response Thomas Fermi
Unable to display preview. Download preview PDF.
References and Footnotes
- 3.Note the factor of a half in front of the gradient term which is absent in the definition used in Ref. 1.Google Scholar
- 9.See the following paper by J. Woo.Google Scholar
- 14.A. W. Overhauser, Bull. Am. Phys. Soc. 15, 344 (1970). I am grateful to Dr. Overhauser for a copy of his preprint.Google Scholar